Im just getting into Airsoft, I have been involved in Paintball for a few years now. It seems hard to determine what guns are going to be upgradeable and which won't be. Im looking at a 300 dollar budget, I would like a decent shooter out of the box, but also want something that can take a bunch of mods down the road. Any advice? So far the one I have been thinking about is this one. http://www.airsoftmegastore.com/4067-gandg-gc16-series-m4-ris-raider-full-metal-airsoft-aeg-rifle-black.aspx or I really like the looks of this one http://www.evike.com/products/41567/ But being new to this game, I don't know who the good manufactures are and aren't. Thanks in advance.